The long-term objective of this proposal is to understand how the cell division cycle is regulated during a normal cell cycle (cell cycle control) and how cell cycle progression is prevented when unreplicated or damaged DNA is detected (checkpoint control). The passage of cells from one stage of the cell cycle to the next is regulated by several distinct controls that act on the transcription of cyclin genes; the degradation of cyclin proteins; the modification of the cyclin-dependent protein kinases (Cdks) by both reversible phosphorylation and by association with regulatory subunits; and finally by intracellular compartmentalization of cyclin/Cdk components and their regulators. The Cdc25 protein phosphatases positively regulate the cell division cycle by activating CDKs and they are also targets of checkpoint control. In humans and rodents, there are three members of the Cdc25 family, designated Cdc25A, B and C. Studies aimed at elucidating how the Cdc25A protein phosphatase is regulated throughout the cell division cycle and in response to checkpoint activation are proposed. In addition, studies aimed at distinguishing the individual contributions made by Cdc25A, Cdc25B and Cdc25C to cell cycle progression and checkpoint control in both mouse and human cells are proposed. Finally, studies will be performed to elucidate how the checkpoint kinases, Chkl and Chk2 are activated by unreplicated DNA and/or genotoxic stress and how these kinases interface with the cell cycle machinery to cause cell cycle delays in the presence of unreplicated or damaged DNA. Because many cancers are neither curable using existing strategies nor readily detectable at early stages there is a need to identify new targets that can be used both as diagnostic probes and as therapeutic targets. The studies outlined in this proposal investigate basic mechanisms of cell cycle control and checkpoint control. Proteins involved in these pathways may one day be used as diagnostic markers or as targets for designing anti-proliferative drugs.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM047017-14A1
Application #
6678535
Study Section
Cell Development and Function Integrated Review Group (CDF)
Program Officer
Zatz, Marion M
Project Start
1992-02-01
Project End
2007-01-31
Budget Start
2003-07-07
Budget End
2004-01-31
Support Year
14
Fiscal Year
2003
Total Cost
$147,298
Indirect Cost
Name
Washington University
Department
Physiology
Type
Schools of Medicine
DUNS #
068552207
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
Origanti, S; Cai, S-r; Munir, A Z et al. (2013) Synthetic lethality of Chk1 inhibition combined with p53 and/or p21 loss during a DNA damage response in normal and tumor cells. Oncogene 32:577-88
Huh, Jiwon; Piwnica-Worms, Helen (2013) CRL4(CDT2) targets CHK1 for PCNA-independent destruction. Mol Cell Biol 33:213-26
Honaker, Y; Piwnica-Worms, H (2010) Casein kinase 1 functions as both penultimate and ultimate kinase in regulating Cdc25A destruction. Oncogene 29:3324-34
Leung-Pineda, Van; Huh, Jiwon; Piwnica-Worms, Helen (2009) DDB1 targets Chk1 to the Cul4 E3 ligase complex in normal cycling cells and in cells experiencing replication stress. Cancer Res 69:2630-7
Kang, Tiebang; Wei, Yongkun; Honaker, Yuchi et al. (2008) GSK-3 beta targets Cdc25A for ubiquitin-mediated proteolysis, and GSK-3 beta inactivation correlates with Cdc25A overproduction in human cancers. Cancer Cell 13:36-47
Tarakanova, Vera L; Leung-Pineda, Van; Hwang, Seungmin et al. (2007) Gamma-herpesvirus kinase actively initiates a DNA damage response by inducing phosphorylation of H2AX to foster viral replication. Cell Host Microbe 1:275-86
Brooks, William S; Banerjee, Sami; Crawford, David F (2007) G2E3 is a nucleo-cytoplasmic shuttling protein with DNA damage responsive localization. Exp Cell Res 313:665-76
Rothblum-Oviatt, C J; Ryan, C E; Piwnica-Worms, H (2001) 14-3-3 binding regulates catalytic activity of human Wee1 kinase. Cell Growth Differ 12:581-9
Thorson, J A; Yu, L W; Hsu, A L et al. (1998) 14-3-3 proteins are required for maintenance of Raf-1 phosphorylation and kinase activity. Mol Cell Biol 18:5229-38
Peng, C Y; Graves, P R; Ogg, S et al. (1998) C-TAK1 protein kinase phosphorylates human Cdc25C on serine 216 and promotes 14-3-3 protein binding. Cell Growth Differ 9:197-208

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